Tablet computers such as Personal Digital Assistants (PDA), cellular phones, and the computing device recently released by Apple Corporation under the trade name IPAD® have become increasingly popular. The simple and slim form factor of such devices is one reason. Another reason is that many of such devices come with a touch sensitive screen, or “touch screen” where user input and computing control are engaged by simply touching the digital display screen. One pioneering example is the cellular phone marketed by Apple under the trade name IPHONE®. This phone has a touch screen that allows navigation of computing function, such as internet navigation, program engagement, and communication (i.e. placement of calls, generation of e-mail, and creation of text messaging) all by directly touching the screen or visual interface.
Direct screen touch navigation has been met with tremendous success in the marketplace because of the ease of navigation and the absence of navigation hardware that is often bulky, difficult or unnatural to use, and often fragile. While direct screen touch navigation overcomes these issues, it is not ideal for some functions such as text input. Particularly, most tablet devices do not allow the user to input text with a full sized or nearly full sized QWERTY keyboard or other format keyboard for full typing capacity with both hands. Neither would the touch sensitive display provide sufficient responsiveness to accommodate normal typing even if size were not an issue. Further, many people simply prefer the feel and performance of hardware based text and data input, such as a slide out keyboard on a cell phone to the feel and performance of text input on a touch screen. Finally, the slim and compact form factor of such devices often trades battery life and memory size for the small and thin overall design.